1645725144 has 64 divisors (see below), whose sum is σ = 4707671040. Its totient is φ = 469647360.

The previous prime is 1645725127. The next prime is 1645725157. The reversal of 1645725144 is 4415275461.

It is a super-2 number, since 2×1645725144² = 5416822499187641472, which contains 22 as substring.

It is a hoax number, since the sum of its digits (39) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 147672 + ... + 158424.

It is an arithmetic number, because the mean of its divisors is an integer number (73557360).

Almost surely, 2^1645725144 is an apocalyptic number.

1645725144 is a gapful number since it is divisible by the number (14) formed by its first and last digit.

It is an amenable number.

1645725144 is an abundant number, since it is smaller than the sum of its proper divisors (3061945896).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1645725144 is a wasteful number, since it uses less digits than its factorization.

1645725144 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11680 (or 11676 counting only the distinct ones).

The product of its digits is 134400, while the sum is 39.

The square root of 1645725144 is about 40567.5380569243. The cubic root of 1645725144 is about 1180.6443727537.

The spelling of 1645725144 in words is "one billion, six hundred forty-five million, seven hundred twenty-five thousand, one hundred forty-four".